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The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk ; Herben, Tomáš (advisor) ; Lepš, Jan (referee) ; Ehrlen, Johan (referee)
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....
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Interactions between animals and plants in urban forests
Dobešová, Jana ; Vojta, Jaroslav (advisor) ; Horčičková, Eva (referee)
INTERACTIONS BETWEEN ANIMALS AND PLANTS IN URBAN FORESTS ABSTRACT This Bachelor thesis focuses on the influence of big mammals (especially Cervidae, wild boars, badgers and foxes) on herb understory in urban forests. Cities are continuously expanding and thus occupy natural habitats of the animals. Therefore, these animals are habituating in urban forests. The specific conditions of both urban and forest habitats and their influences on animal and plant distribution are mentioned. From the possible influences of animals on herb understory, special emphasis is put on herbivory, which can affect individuals, populations and even whole plant assembly. The influence of trampling, urination and burrowing are also investigated. Finally there is a summary of big mammals' influence in relation to human influences. Key words: Urban forests, herbivory, herb layer, disturbation, nutrients, large mammals
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Plant traits determining plant-herbivore interactions
Medová, Tereza ; Münzbergová, Zuzana (advisor) ; Skuhrovec, Jiří (referee)
Plants are constantly endangered by herbivores. Plants have adapted and created a wide arsenal of defences during approximately 410 million years of coexistence. Their role consists of fading the herbivores off or reduce suffered damage. This bachelor's thesis focuses on mechanisms that were proven to serve as plant defences. It is specifically about interactions between invertebrate herbivores and plants of terrestrial ecosystems. Prediction of herbivory by some traits is mentioned as well. Information about characteristics of plants which affects preferences of herbivores is interesting due to its possibility of aplication in agriculture or biological control of invasive species. Powered by TCPDF (www.tcpdf.org)
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Interactions of herbivore funtion gourps and Succisa pratensis
Šulcová, Hana ; Janovský, Zdeněk (advisor) ; Roubíčková, Alena (referee)
Herbivory is one of most important factors which form meadow ecosystems. These ecological communities have one of the biggest variety of species in Central Europe and their research is important in terms of management of protected species as well. Localities which has a similar importance, is also a meadow ecosystem with occurrence of Succisa pratensis, the only host plant for rare butterfly Euphydryas aurinia. Research of Succisa and its other herbivores can improve a protection of this particular butterfly. Effects of herbivores of Succisa were examined by several experiments. The first one was a field cage experiment. Its aim was to detect what kinds of herbivores (rodents and invertebrates) are involved in herbivory of leaf rosettes of Succisa and what is their impact on the fitness of these plants. The intensity of herbivory of Succisa was measured for over two vegetation seasons on the month bases. In this experiment were also examined effects of surrounding vegetation on the studied plants of Succisa. The second experiment was performed in a garden. Its aim was to clarify the role of herbivores of leaf rosettes, stalks and their interactions on the fitness of Succisa. The third experiment was concerned to true bugs, which are pre-dispersal predators of seeds of Succisa. Their effects on...
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Mollusc grazing and secondary metabolites of lichens
Černajová, Ivana ; Svoboda, David (advisor) ; Vondrák, Jan (referee)
In contrast to the much that is known about herbivory and its consequences, lichenovory has seldom been studied. Recently, studies confirming the anti-feedant role of lichen secondary metabolites were brought out and hypotheses considering the nature of these interactions were introduced. Also, a few papers dealing with the ecological consequences of lichenovory were published lately. My thesis was aimed on the secondary metabolites issue and the preferences of the lichen feeders in the natural conditions. Six epiphytic lichen species containing secondary compounds (Parmelia sulcata, P. saxatilis, Parmelina tiliacea, Melanelixia glabratula, M. subaurifera, M. glabra), two without them (Melanohalea exasperata, M. exasperatula) and two species of gastropods that naturally climb the trees to feed on lichens (Lehmannia marginata, Cochlodina cerata) were selected for grazing experiments. The deterring role of the lichen compounds was proven. These were also identified using thin-layer chromatography. Subsequently, a transplantation experiment was carried out. It was focused on specifying the preferences of lichen grazers in their natural habitat. The genus Melanohalea that does not contain any secondary metabolites was strongly prefered. No significant preferences among the other species used in the...
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The impact of herbivores on plant population dynamics: The importance for biological control of invasive plants
Šulcová, Hana ; Dostál, Petr (advisor) ; Kindlmann, Pavel (referee)
Herbivory is one of the most important relations between plants and animals. The herbivores affect plant populations not only by grazing, but also by trampling and disturbing the vegetation. Herbivores have also great potential to affect the population dynamics of particular plant species. The aim of this thesis is to evaluate the effect of herbivores on plant population dynamics and to interpret it in relation to biological control of invasive plants. When evaluating the effect of herbivores, it is necessary to keep in mind the fact that herbivores don't affect only plants but also each other through direct as well as indirect competition. The use of different herbivore species to supress the invasive plants may not necessarily be effective. The range of the effect of herbivores on plant population dynamics depends also on the environmental conditions. Habitats with infrequent disturbances and high competition levels among plants increase the effect of biological control, because high competition facilitates competitive exlusion of the target plant species. Different life-histories of plants play are also important in terms of biological control mainly the life-span and the endurance of the seed bank affect the results. Monocarpic species with short-lived seed bank can be relatively easily reduced by...
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The effect of ants predation risk for herbivorous insect
DRAG, Lukáš
This thesis is the first step to evaluate the relationship between ant activity (predation risk) and the leaf damage caused by herbivorous insects. Tuna baits which were used in 1, 2 and 3 hours intervals to attract different species of invertebrates. The degree of herbivory was measured as the proportion of leaves that had been chewed or mined by herbivores. The most abundant and frequent potential predators were ants. All ant species were determined and patterns of their activity analysed.
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